JPS61252802A - Ladder type locking device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates to multistage gas turbine engines, and more particularly to a turbine rotor assembly comprising two rotor stages.

Background Art In a twin spool type gas turbine engine, a working medium gas is first compressed in a low pressure compression section,
It is then compressed in a high pressure compression section and used as an oxidizing agent in generating hot fluids. The hot fluid is passed through the high pressure turbine section and then into the low pressure turbine section where it is expanded. The high pressure turbine drives a high pressure compressor via a high pressure shaft, and the low pressure compressor is driven by the low pressure turbine via a low pressure turbine shaft located within the high pressure turbine shaft. Within the turbine section, a rotor stage attached to the turbine shaft consists of a hub, a disk, and a plurality of blades disposed around the periphery of the disk. The flow path geometry is defined and maintained by circumferentially extending air seals between the two rotor stages. A plurality of blades extend radially outwardly across the flow path for the working medium gas to extract energy from the working medium gas flowing between the blades. The energy thus extracted is transferred to the turbine shaft via the disk and hub.

High pressure turbines typically include two rotor stages, with approximately equal amounts of work extracted from each rotor stage. Modern turbofan engines can generate more than 60,000 bonds (27,216 Jl) of thrust. In large turbofan engines, the torque transmitted from each high-pressure turbine rotor stage to the high-pressure turbine shaft is approximately 500,000 inches bond (500,000 inches bond).
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The main design goal of a complex turbofan engine is to
The objective is to facilitate engine assembly and disassembly while maintaining the structural integrity of the engine and limiting the weight of the engine. It would be highly beneficial to limit the size and weight of the disk portion of a turbine rotor stage while maintaining the structural integrity of the turbine rotor assembly. It is also advantageous to eliminate holes or flanges for connecting the two turbine rotor stages to each other, since these can maintain material strength in the face of high centrifugal loads and their fluctuations.

It is known in the art to attach two rotor stages of a high pressure turbine to each other using permanent means such as bolts or welding. It is also known to fix the rotor stage to the turbine shaft by bolts or welding. These methods of attaching the two rotor stages to each other make the gas turbine engine complex and difficult to assemble and disassemble. Additionally, the provision of bolt holes or flanges in the disks necessary to attach adjacent rotor stages to one another requires thicker disks and heavier rotor stages.

Bolt holes also reduce the load carrying capacity and structural integrity of the disk. On the other hand, seven lunges increase the weight of the rotor stage and also create vibration problems that must be taken into account in design. The prior art, such as U.S. Pat. No. 3,997.962, shows the use of splines to attach two rotor stages to a single turbine shaft.

U.S. Pat. No. 4,004,860 also teaches that the hub of the first rotor stage be aligned with the turbine shaft so that the turbine shaft, the hub of the first rotor stage, and the hub of the second rotor stage are all concentric. The hub of the second rotor stage is shown splined to the hub of the first rotor stage. The inventors have found that in such designs it is difficult to maintain concentricity between the hub and the turbine shaft. Such attachment means cause excessive wear on the splines, which compromises the structural integrity of the hub-to-hub and turbine shaft-to-hub connections. It is also desirable to be able to hold the turbine rotor assembly together so that the turbine rotor assembly can be easily and safely transported for installation in an engine.

DISCLOSURE OF THE INVENTION One object of the present invention is to provide a turbine module that includes at least two rotor stages and one stator stage and that can be transported as one piece and assembled on the turbine shaft.

Another object of the invention is to combine the turbine rotor assembly into one piece so that the turbine rotor assembly consisting of two rotor stages can be transported as one piece and can be assembled as one piece on the turbine shaft. The purpose of the present invention is to provide a device for holding the device.

Yet another object of the invention is an apparatus for securing together components of a turbine rotor subassembly consisting of two rotor stages, the method comprising: securing circumferential alignment between the two rotor stages; An object of the present invention is to provide a device that can properly secure the following conditions.

According to the invention, a gas turbine engine includes a first rotor stage having a first hub having a plurality of first lugs extending radially inwardly; a second rotor stage having a second hub having a plurality of radially inwardly extending second lugs cooperating with the first lug to form a projection; a ladder shape comprising an elastic metal band having a plurality of circumferentially disposed holes in which the protrusions are radially fitted, and a split for fixing the two turbine rotor stages to each other; and a locking device.

According to one preferred embodiment of the invention, the first and second rotor stages are part of a larger turbine module that includes a single stage of stator vanes disposed between the two rotor stages.

A major advantage of the present invention is that the two hubs of the turbine rotor assembly can be secured together, thereby facilitating assembly and disassembly, transportation, and mounting on the turbine shaft of the turbine rotor assembly.

Another advantage of the present invention is that there is no need to bolt or weld the two rotor stages together, and an axially effective interstage seal is provided between the two rotor stages of the turbine rotor assembly. It can be captured and supported in the radial direction.

The coaxial and eccentric thrust bearing relationship of the two hubs allows them to be mounted on the turbine shaft individually or as part of a rotor assembly or as part of a turbine module that includes a stator structure. can be placed. If the two disks are required to be placed on the turbine shaft as a single unit, such as a rotor assembly or turbine module, the rotor assembly may be fitted with a mounting device or other type of locking device, as described in more detail below. Means are provided for holding them together during their installation.

One major advantage of the present invention is that an individual rotor stage or a rotor assembly of two rotor stages can be attached to the turbine shaft while maintaining a valid connection between the two rotor stages and the turbine shaft. It can be easily installed. Another advantage of the present invention is that an interstage seal can be effectively captured and supported between two o'9 stages without the need to bolt or weld the two rotor stages together. . Yet another advantage of the present invention is a turbine module that includes both rotating and stationary structures and that can be easily and effectively positioned on a turbine shaft.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

BEST MODE FOR CARRYING OUT THE INVENTION Turbine module configured according to the present invention 5
is shown mounted on the high-pressure turbine shaft 20 of the gas turbine engine in FIG.
In the figure, it is shown separated from the turbine shaft. Module 5 includes a turbine rotor assembly 10 and a stator assembly 94. Rotor assembly 10 includes a first rotor stage 30 and a second rotor stage 40. First rotor stage 30 includes a first hub 32 and a first disk 34 cantilevered from the hub.

The second rotor stage 40 includes a second hub 42 and a second disk 44 cantilevered from the hub. A first disc rim 36 supports a first plurality of turbine blades 38 .

A second disc rim 46 also supports a second plurality of turbine blades 48 . An annular interstage seal 92 is disposed between the disks 34 and 44 and is radially supported by the disks so as to "rotate" therewith.

Stator assembly 94 includes a single stage of stator vanes 102 disposed between blades 38 and 48, a first annular outer air seal 96 surrounding blade 38, and a second annular outer air seal surrounding blade 48. 98. Inner stator shroud 104 supports a seal land 105 that cooperates with interstage rotating seal 92 .

Seals 96,98 and stator vanes 102 are secured by suitable means to turbine case section 106, which section forms part of stator assembly 94. More specifically, the forward end of the first outer air seal 96 and the outer shroud 100 are attached to the first 7 langes 108 of the turbine case section 106, and the aft end of the second outer air seal 98 and the outer shroud 100 are attached to the first seven flange 108 of the turbine case section 106. It is attached to the second 7 flange 110 of the turbine case section 106. ``Turbine blades 38 and 48 extract energy from the working fluid. The energy thus extracted is transferred to the turbine shaft 20 via the first 0-9 stage aO and the second rotor stage 40. The turbine shaft 20 has a first external spline 54
and a second external spline 64, the external splines being axially spaced from each other and having the same diameter. The first hub 32 has a first internal spline 52 that is coaxial with and eccentric to a second internal spline 62 on the second hub 42. There is. Internal tooth spline 52
and 62 also have the same diameter. A first internal spline 52 provided on the first hub 32 engages a first external spline 54 provided on the turbine shaft 20, thereby causing the first rotor stage 30 to be closer to the turbine shaft 20. It is designed to be able to transmit torque.

On the other hand, a second internal spline 62 provided on the second hub 42 engages a second external spline 64 provided on the turbine shaft 20, thereby causing the second rotor stage 40
This allows more torque to be transmitted to the turbine shaft 20. The large torque transmitted by each rotor stage to the turbine shaft 20 is approximately 500,000 inch bonds in a large turbofan engine. Because the diameters of external splines 54 and 64 are equal, hubs 32 and 42 can easily slide forward along turbine shaft 20. This also facilitates machining splines into the turbine shaft and hub.

Preferably, the diameters of each spline are equal to each other;
In the present invention, the diameters of these splines do not necessarily have to be equal to each other. First internal spline 5
The first hub 32 and the second hub 42 may be individually slidably fitted onto the turbine shaft 20 as long as the inner diameter of the second internal spline 62 is the same as or larger than the inner diameter of the second internal spline 62. Alternatively, they may be attached to each other as part of a subassembly, ie, a turbine module.

A cylindrical ridge 72 extends from the first annular recess 74 for receiving the forward end 73 of the second hub 42 and thereby preventing relative radial displacement of the first and second hubs. It is formed at the rear end of the hub 32. The front end 73 of the hub 42 abuts the hub 32 in the axial direction so that the hubs 32 and 42 are in a thrust bearing relationship with each other. A nut 120 having an internal thread 122 is threaded onto a thread 26 located behind the second external spline 64 proximate the aft end of the turbine shaft 20 . Nut 120 has a thrust bearing relationship with second hub 42 and is used to tighten turbine rotor assembly 10 against stop 24 .

Stop 24, in the preferred embodiment shown, is a bearing sealing surface of a bearing (not shown) located immediately forward of the turbine. Ring-shaped locking device! 130 has a third external spline 134 that engages with a third internal spline 124 provided on the nut 120. Rock 1 again!
11130 has a plurality of protrusions 132 disposed circumferentially around its front end, and these protrusions engage with a plurality of notches 28 provided at the rear end of the turbine shaft 20. This prevents the nut 120 and the locking device 130 from rotating relative to the turbine shaft 20. In addition, the locking device @130 has a plurality of rear protrusions 136.
The protrusions extend radially outwardly into an inner groove 126 in the nut 120. Projection 1
A first locking song 140 and a second locking ring 142 located within the inner groove 126 on opposite sides of the locking device 130 prevent axial displacement of the locking device 130.

2 and 3, a plurality of radially inwardly extending first lugs 35 are disposed circumferentially around the rear end of the first hub 32 and are radially A plurality of inwardly extending second lugs 45 are disposed circumferentially about the forward end of the second hub 42 . These two sets of lugs are #t4 to each other! 3, and abut each other to form a protrusion 80 extending radially inward.

These two sets of lugs 35 and 45 ensure that when they are axially aligned, the teeth of the internal splines 52 and 62 are also axially aligned with each other so that the turbine blades 38 and 48 are aligned relative to each other in the desired circumferential direction. They are arranged in the following positional relationship.

If the rotor stages 30 and 40 need to be placed on the turbine shaft 20 as one piece, such as a rotor assembly or turpin module, or if the rotor assembly 10 or turbine module 5 needs to be transported, In order to fix the first hub 32 to the second hub 42 in the axial direction so as to be able to transport the turbine 0-Yumei solid body etc., a rectangular hole 61 and a split 63 arranged in the circumferential direction are provided. a ladder-shaped locking device 6 including an annular elastic metal band with
0 is used.

The uninstalled diameter of the ladder locking device f160 is larger than the desired diameter when it is assembled, so that the locking device f160 is in a predetermined position with the protrusion 80 extending through the hole 61. At some times, it generates a radially outward spring force against the inner circumferential surfaces of hubs 32 and 42. Protrusion 80
is a tight fit in hole 61, thereby allowing rotor stages 30 and 4
0 are prevented from being significantly displaced relative to each other in the axial direction or in the circumferential direction. The interstage seal 92 is also rotor stage 3
It is held tightly in place between 0 and 40.

When the turbine module 5 is assembled onto the turbine shaft 20 (see FIG. 1), the splines 52 and 62, the nut 120, and the locking arrangement M130 maintain the proper angular and axial position of the rotor stages 30 and 40. The ladder-shaped locking device 60 thus performs no function related to engine operation during engine operation, but allows the turbine module 5 to be removed as one piece when maintenance of the engine is performed.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a high pressure turbine section of a gas turbine engine incorporating the present invention. FIG. 2 is a partial view of a portion of the high pressure turbine section of FIG. 1 with the turbine shaft removed. FIG. 3 is a perspective view of a locking device used to hold two rotor stages of a turbine together when the rotor assembly is installed into an engine. 5... Turbine module, 10... Turbine rotor assembly, 20... Turbine shaft, 24... Stopper. 26... Screw, 30... Rotor stage, 32... Hub, 34... Disc, 36... Disc rim, 38
... Turbine blade, 40 ... Rotor stage, 42.
... Hub, 44 ... Disc, 46 ... Disc rim, 48 ... Turbine blade, 52 ... Internal tooth spline, 54 ... External tooth spline, 60 ... Ladder type locking device, 61 ...hole. 62...Internal tooth spline, 63...Split, 6
4... External spline, 72... Ridge, 73... Front end, 74... Annular recess, 80... Projection, 92...
...Seal between stages. 94... Stator assembly, 96.98... Outer air seal, 100... Outer shroud, 102...
・Vane, 104...Inner stator shroud, 1
05... Seal land, 106... Turbine case section, 110... Flange, 120... Nut, 122... Internal thread, 124... Internal spline, 126... Inner groove, 130 ...locking device, 132
... Protrusion, 134 ... External spline, 136 ...
・Protrusion, 140.142...Rockring Patent Applicant: United Chicnolosis Corporation

Claims (3)

[Claims] (1) A ladder-shaped locking device for fixing two turbine rotor stages along the axis, with multiple holes arranged in the circumferential direction, and the diameter when not installed is greater than the diameter when installed. A ladder-shaped locking device that also includes an annular elastic metal band with a large split. (2) a shaft-mounted turbine rotor assembly including a first hub and a first disk, the first disk having a first rotor stage attached to the first hub; , disposed proximate the first rotor stage and including a second hub and a second disk, the second disk attached to the second hub, and the first rotor stage a second rotor stage disposed in thrust bearing relationship with the first hub; a plurality of first lugs disposed circumferentially on the first hub and extending radially inwardly; a plurality of second lugs disposed circumferentially on the second hub and extending radially inwardly, the plurality of second lugs being proximate to and corresponding to the corresponding first lugs; a plurality of second lugs cooperating with each other to form a plurality of circumferentially disposed protrusions; and a plurality of holes equal in number to the protrusions, the second lugs extending overlapping the protrusions; an annular band having a split therein, each of the protrusions being disposed within the corresponding hole, the band controlling the angular and axial positional relationship of the first hub with respect to the second hub; A turbine rotor assembly including: an annular band configured to (3) a shaft-mounted turbine module including a first hub and a first disk, the first disk having a first rotor stage attached to the first hub; a first attachment means for attaching a first hub to the shaft; and a second hub and a second disk disposed proximate the first rotor stage, the second disk being attached to the first rotor stage. a second rotor stage mounted on a second hub; and a second rotor stage mounted on the shaft such that the second rotor stage is disposed in a thrust bearing relationship with the first rotor stage. a second attachment means coaxial with the first attachment means and eccentric from the first attachment means; a second attachment means disposed circumferentially on the first hub and radially inwardly disposed on the first hub; a plurality of first lugs extending toward the second hub; and a plurality of second lugs disposed circumferentially on the second hub and extending radially inwardly, each of the plurality of second lugs extending radially inwardly from the second hub. a plurality of second lugs disposed proximate to the first lugs and cooperating with the corresponding first lugs to form a plurality of circumferentially disposed protrusions; and a number of the protrusions. an annular band having a plurality of holes equal to the number of holes and having splits extending overlapping the protrusions, each of the protrusions being disposed within a corresponding one of the holes; an annular band configured to maintain the angular and axial positional relationship of the first hub relative to the hub; and an annular band connected to and extending radially outwardly from the first disk. a plurality of first blades connected to the second disk and extending radially outward from the second disk; and the first and second rotors. an annular interstage seal radially supported by a stage and captured axially between the first rotor stage and the second rotor stage; an inner shroud; an outer shroud; and a plurality of stator vanes extending between the outer shroud and the outer shroud, the stator vanes having an annular shape disposed in a sealing relationship with the interstage seal in a radially outward direction from the interstage seal. a stator stage; a first outer air seal means surrounding the plurality of first blades; a second outer air seal means surrounding the plurality of second blades; and a second outer air seal means surrounding the stator stage. a case having integrally formed and axially spaced apart first and second annular attachment means, said first annular attachment means connected to said first outer air seal means; The second annular attachment means includes a case connected to the second outer air seal means.